The definition of whore is changing in the 21st century. Whore is seldom used in the US anymore to refer to prostitutes. More often it is used for the following:
A whore is 1. A promiscuous woman of exceptional sexual expertise and experience. 2. A woman who has sex with almost anyone for the pure love of sex and pleasure. 3. An archaic term for prostitute.
Mary is such a good whore she could teach an advanced class in sex!